2) CleanSpace High Efficiency (HE) Filters are a NIOSH approved particulate filter. The layer of activated multi-gas carbon provides Nuisance level relief from Cyclohexane, Sulfur Dioxide, Chlorine, Hydrogen Sulfide, Ammonia and Formaldehyde, NIOSH does not evaluate the effectiveness of Nuisance Odor Filters for the removal of Nuisance Odors. If used against Formaldehyde, this filter must be disposed of at the end of every shift. These filters are suitable for nuisance level exposure not exceeding OSHA PEL. Please refer to DATA Sheets – CST1006 CleanSpace CST High Efficiency (HE) Filter USA and PAF-1008 CleanSpace Nuisance Filter USA for NIOSH Approvals – in Resources.